Venturi plug



June 19, 1956 D. G. FAUST 2,751,045

VENTURI PLUG Filed June 12, 1955 2 Sheets-Sheet 1 INVENTOR.

Delbert G. Faust kainw ATTORNEY June 19, 1956 D. G. FAUST 2,751,045

VENTURI PLUG Filed June 12, 1953 2 Sheets-Sheet 2 IN V EN TOR.

Delberf 6. Faust ATTORNEY United Patent 2,751,045 Patented June 19, 1956 VENTURI PLUG Delbert G. Faust, Englewood, Colo., assignor to C. A. Norgren C0,, Englewood, Colo., a corporation of Colorado Application June 12, 1953, Serial No. 361,249

7 Claims. (Cl. 184-55) This invention relates to venturi plugs or atomizers for aerosol type lubricators whereby the amount of oil dispensed by such a lubricator may be controlled by controlling the pressure drop across the venturi section of the lubricator.

In my copending application, Serial No. 330,544, filed January 9, 1953, now Patent No. 2,710,073, issued June 7, 1955, entitled Airline Lubricator there is described an aerosol type lubricator wherein oil is syphoned from a supply source by means of an eductor or venturi for mixing the oil and air within the venturi section. The oil is atomized in the venturi and is then either discharged into the airline, or it is discharged into a settling space to remove large particles therefrom and subsequently inject the fine articles of oil suspended in air into the air stream. The venturi plug of the present invention provides an improvement for such lubricators, as it provides means for controlling the pressure drop across the venturi section and consequently the rate at which oil is syphoned from the supply.

The amount of oil required for lubrication of moving parts by a suspension of small particles of oil in a stream of air varies from bearing surface to bearing surface, but generally it is only feasible to produce one type of lubricator to be applicable for a large number of different uses. Also, a bearing may require a different amount of lubrication under different operating characteristics. Accordingly, the present invention provides means for controlling the amount of lubricant in relation to the amount of air passing through such a siphon type lubricator.

The present invention comprises a venturi plug for aerosol lubricators which has an air by-pass set at an angle to the venturi or eductor air inlet and substantially parallel to an outlet, whereby the pressure drop across the venturi section may be varied over a wide range, and the amount of oil drawn from the supply and atomized into the air stream may likewise be varied. The angle between the inlet and the by-pass is preferable such that when the by-pass is fully closed the outlet is fully closed and the inlet is parallel to the stream fiow and the venturi section passes substantially all air which passes through the lubricator. In this setting, due in part to a ram effect of air into the inlet, there is the greatest pressure differential across the venturi section so that the maximum amount of oil is drawn from the oil supply for atomization into the air stream. When the by-pass is fully opened, the inlet is at an angle to stream flow, the outlet is parallel to stream line flow, and a proportionately smaller amount of air passes through the venturi section and, likewise, a proportionately smaller amount of oil is drawn through the venturi section. In this setting the inlet is near the wall of the conduit in about the slowest flow zone of the conduit, and the air passing the by-pass creates a low pressure zone around the outlet so air is drawn from the venturi through the outlet thereby lowering the pressure drop across the venturi section.

It is therefore, an object of the present invention to provide a variable means for introducing atomized oil into an air stream.

Another object of the present invention is to provide variable means for introducing atomized oil into an air stream by varying the oil flow through a venturi section or eductor means.

These and other objects of the present invention may be apparent by having reference to the following description and appended drawings in which;

Fig. l is a cross sectional side elevation of a venturi plug according to the invention, in position in an air conduit.

Fig. 2 is an end elevation of the device of Fig. 1;

Fig. 3 is a top-sectional view of the device of Fig. 1 taken along section lines 3-3;

Fig. 4 is a sectional view similar to Fig. 3 showing the plug in a different upward position.

In the device selected for illustration, the venturi plug comprises a body 10, having an oil passage 12 partially therethrough starting on the side adjacent the top of the plug. The plug is rotatably sealed in a lateral bore 14 substantially perpendicular and intersecting a fluid conduit 13. The passage 12 internally terminates in a small tube 18 inside a chamber 20 which completely encircles the tube 18. The chamber 20 has an outlet 22 which is of smaller diameter than the chamber. The tube 18 extends a short distance into the chamber outlet 22, thereby forming the throat of an eductor, or a venturi or venturi section, as such eductor type devices are commonly called in the art.

The chamber 20 has an inlet 23 facing upstream and a smaller outlet 25 facing downstream. The outlet 25 is of substantially smaller diameter than the inlet 23 whereby only a fraction of the air entering the inlet is exhausted through the outlet. A by-pass 26, formed by cutting a small section out of the side of the plug, is substantially parallel to the outlet 25. I11 a device proportioned as shown, the inlet is formed at an angle of about 35 degrees from the center line of the outlet, and away from the by-pass. The angle between the inlet and the outlet is such that when the inlet is aligned with stream flow, substantially in the center of the conduit, the outlet is closed by the side of the passage, as is the by-pass. By varying the passage dimensions in relation to the plug, the angle between the inlet and outlet may be varied.

The plug is sealed in the passage by means of an O ring seal 30 at the lower end thereof and at the upper end by means of another 0 ring seal 32. An 0 ring seal 34 above the seal 32 forms a small chamber 36 between the plug and the bore 14. An oil supply passage 38 from an oil reservoir interconnects the chamber 36 and consequently the passage 12, so that there is a connection with the oil supply no matter which way the plug is turned.

In operation, the plug is fitted into the air conduit of a lubricator, such as described in my above mentioned copending application or in a lubricator which has an oil reservoir suspended below the air conduit and which has an oil supply line leading to the top of the lateral passage, and which has a passage leading from the oil reservoir on the downstream side of the plug to the airline. The lubricator is connected to an airline, and the oil reservoir is partially filled with a light oil. The airline is then opened to permit air or other gas under pressure to pass through the lubricator. The plug is turned to a position corresponding to the approximate flow of air. A scale on top of the plug may be provided to indicate the plug position. A wrench or screw driver slot 17 is provided for ease of turning the plug. The plug may thus be set by experimentation for the amount of lubrication required, or by calibrating air flow rates to average lubricant requirements at those rates. The plug may, of course, be adjusted during actual running to fit the requirements of the particular application.

If the plug is set in the position of Fig. 3, air entering'inlet 13 is substantially passed directly into outlet 11 throughthe by-pass 26. A small'amount of air enters venturi inlet 23 into the chamber 20. Some of the air from the chamber exhausts through the-outlet 25 into the passage .outlet .11. The large volume of air passing through the by-pass creates a low pressure or eductor action near the outlet 25. This low pressure draws more air from the chamber than .would normally 'flow out without the added force of the low pressure area. The remaining air which. has entered the chamber 26 passes through the venturi throat and reduces the pressure in passage '12 by a venturi or eductor action. The reservoir is at substantially line pressure, and the pressure diflerential between the reservoirand the passage 12 forces oil up the supply tube 38 into the venturi section where his admixed and atomized into the The airoil mixturepasses through the venturi throat 22 into passage 40 and lateral passages 41 in a ditlusion plug 42. The diflusion plug exhausts into the upper part of the reservoir, and the change in velocity into the reservoir space from diffusion plug and the diffusion plug itself aids in separating large particles of oil from the mixture. The mixture then is a suspension of fine oil particles in air. The suspension or mist passes through passage 43 into outlet 11 where it joins and isadmixed with the air that has by-passed the venturi section. This setting produces the smallest pressure drop and, therefore, the smallestramount of oil mist in the air stream.

Thesetting of Fig. 4 produces the greatest amount of oil mist, since substantially all air entering the lubricator passes through venturi inlet 23 and the venturi. This creates the greatest pressure dilferential across the venturi section, and the greatest amount of oil is therefore drawn through'the venturi section. The mixture of oil and air then passes through the difiusion plug into the reservoir, where large oil particles are separated, and out through passage 43-into the outlet 11.

Theplug may be turned to any point intermediate of the two described, to obtain a large variety of pressure differentials across the venturi section. The plug may also be turned to adjust the pressure differential for varying air flows and/or lubricant requirements. The lubricator provides one simple adjustment for controlling pressure diflerential across the venturi section, and, hence, the amount of lubricant atomized into the air stream. One lubricator may, therefore, be connected into any .of several sizes of air conduits, and the required amount otluoricant is quickly controlled and adjusted by merely turning the plug to the desired point.

The venturi plug may be varied to be utilized for various modifications of aerosol lubricators. For instance, side outlet connection to the oil supply may be omitted and oil supply for the venturi extended up through the top of the .plug. Such an arrangement would be necessary where a drip tube is provided abovethe venturi. Other modificationsimay occur to those skilled in the art .WiihOllt deviation from the scope and spirit'of the appended claims.

I claim:

1. A venturi plug of the type described, comprising a cylindrical rotatable plug constricting the opening of a fluid carrying conduit, a lubricant passage in said plug, on end of said passage debouehing into a venturi throat internally of said plug, an annular chamber encircling saidpassageiadjacent and communicating with said throat, an inlet passage to said chamber having an opening facing upstream whereby fluid enters said chamber and exhausts throughsairl throat forming a low pressure area in said lubricant passage, an outlet passage from said chamber of smaller cross sectional dimensions than said inlet passage having anopening facing downstream, and by-pass means cooperatively interconnected with said plug for providing a variable passage for fluid around said plug whereby rotation of the plug moves the inlet opening from fluid flow alignment to an angle incidentthereto and simultaneously moves the by-pass means and outlet openingfrom closed to open position.

2. A venturi plug of the type described, comprising a plug constricting the opening of a fluid carrying conduit, a lubricant passage in said plug, one end of said lubricant passage debouching into a venturi throat, an inlet passage having an upstrearn opening to said throat whereby fluid exhausting through said throat forms a .low pressure area-in said lubricant passage, -said-inlet passage being normal to said'lubrieant passage,=-and bypass means cooperatively interconnected with'sai'd'plug for providing a variable passage for fluid around said plug whereby rotation of theplug moves the inlet opening from fluid flow alignment-to an angle incident thereto and moves the bypass means from closed to open position.

3. [x venturi plug or" the type described, comprising a cyliu al rotatable plug constricting .the opening ,of ,a fluid carrying conduit, a partial passage in said .plug normal to the fluid flow, one end ofsaidpartial passage deoouching into a venturi throat, an annularehamber encircling said passage adjacentand communicating With said throat, an inlet passage having an upstreamopening to said chamber whereby fluid enters said-chamber and exhausts through said throat forming a lowpressure area saidpartial passage, an outlet passage having a. down stream opening from said chamber of smaller diameter than said inlet, said inlet and said outlet being normal to said passage and obtuse to eachother, and hy-pass means cooperatively interconnected withsaid plugfor providing a variable passage for fluid around said plug whereby rotation ot the plug moves the inlet: openingt'rom fluid flow alignment to an angle incident thereto, and movesthe bypass means and outlet opening from closed to:op,en,position.

4. A venturi plug of the type described, com-prisinga rotatable body adapted to eonstricta fluid carring conduit, a chamber in said body,iafiuid inlet passage having an upstream opening to said chamber, and outletpassagc having a downstream openingifor said chamber of substantially smaller cross sectional area than said inlet,..a .venturi exhausting said chamber, a lubricant passage in said body terminating in said venturi whereby fluid ex hausting through said venturi creates a lowpressurearea in said lubricant passage, means connecting said-lubricant passage Witha supply source for any rotational position of saidpiug, said inlet opening facing upstream of said fluid conduit and said outlet opening facing downstream of said fluid conduit spaced from saidinlet, and bypass means cooperatively interconnected with said plug for providing a variable passage for fluid around said plug whereby rotation of the plug moves the inlet opening from fluid flow alignment to an angle incident thereto and simultaneously moves saidbypass meansand said outlet opening from closed to open position.

'5. A-venturiplug of the type described comprising a rotatable body adapted to constrict a compressed air conduit, means associated with said body and said conduit for forming an annular compartment therearound, said. compartmentlbeing interconnected with alubricant supply. a chamber within saidbody, an inletpassagehaving an tap-streamair-inlet opening for said chamber, an outlet passage havingla down-stream outlet opening for said chamber of substantially sma ler cross sectional area than said inlet, a venturi exhausting said chamber, ,a lubricant passage ,in said body terminating at one end in said compartment and the other end in said venturi whereby it passing through saidventuri creates a low pressure area in said lubricant passage and draws lubricant from said supp y, said inlet opening being at an obtuse angle from said ouiilet'openingand,anotclrby-pass in the sidect said body "for providing a variable passage'for air around said plug whereby said inlet opening may be indexedjfrc-m maximum to minimum flow of air and said "by-pass and said outlet opening are simultaneously indexed from closed to open position.

6. A venturi plug of the type described, comprising a rotatable body adapted to constrict a compressed air conduit, means interconnecting said body with a lubricant supply, eductor means in said body adapted to draw lubricant from said supply under the influence of flowing air, air inlet means for said eductor, outlet means associated with said eductor of substantially smaller cross sectional area than said inlet, and by-pass means cooperatively interconnected with said plug whereby rotation of said plugs varies the fiow of air through said eductor.

7. A venturi plug of the type described, comprising a rotatable body adapted to constrict a compressed air conduit, eductor means internally or" said body, air inlet means for said eductor, air outlet means for said eductor of smaller dimensions and spaced from said inlet means, means interconnecting a lubricant supply with said eductor whereby under the influence of a stream of air passing therethrough lubricant is drawn into said eductor and admixed with air passing therethrough, and notch by-pass means in said plug and cooperative wtih said conduit for providing a variable air by-pass around said plug whereby indexing said inlet from maximum to minimum flow simultaneously indexes said by-pass means and said outlet from closed to open position.

References Cited in the file of this patent UN 1T ED STATES PATENTS 1,477,280 Pordes Dec. 11, 1923 1,551,098 Gilman Aug. 25, 1925 1,688,946 Terry Oct. 23, 1928 2,512,366 Nast June 20, 1950 

